In distribution systems, widely used are distribution facilities whose capacity can withstand the maximum load generated in such distribution systems. Some already-known technologies estimate the maximum load generated in distribution systems. With such conventional technologies, the amount of power consumption in a month is calculated based on the meter-reading information acquired by an electric power company every month and the maximum load is estimated based on the amount of power consumption in a month. Conventional technologies are described in Japanese Laid-open Patent Publication No. 2012-147675, for example.
With the conventional technologies, the maximum load is estimated larger to some extent to prevent a situation in which the maximum load exceeds the capacity of a distribution facility. If the capacity of the distribution facility is selected, therefore, based on the estimated maximum load, the distribution facility with excessive capacity may be selected. In addition, the maximum load may be estimated due to a low-voltage distributed generation system in the distribution line. Furthermore, if the maximum load is not estimated because a reverse power flow occurs, a facility may be selected with a capacity smaller than the actual load.